Number

68

68 is a composite number, even, a calendar year.

Arithmetic Number Deficient Number Evil Number Flippable Happy Number Pernicious Number Perrin Number Recamán's Sequence Year

Historical context — 68 AD

Calendar year

AD 68 (LXVIII) was a leap year starting on Friday of the Julian calendar.

Excerpt from Wikipedia (en) ↗ · Licensed CC BY-SA 4.0 · English fallback Read the full article on Wikipedia →

Historical context — 68 BC

Calendar year

Year 68 BC was a year of the pre-Julian Roman calendar.

Excerpt from Wikipedia (en) ↗ · Licensed CC BY-SA 4.0 · English fallback Read the full article on Wikipedia →

Year facts

Year type: Leap year
Divisible by 4 and not by 100; February has 29 days.
Days in year: 366
ISO weeks: 52
Started on: Sunday
January 1, 68
Ended on: Monday
December 31, 68
Friday the 13ths: 3
3 Friday the 13ths this year.
Decade: 60s
60–69
Century: 1st century
1–100
Millennium: 1st millennium
1–1000
Years ago: 1,958
1958 years before 2026.

In other calendars

Hebrew: 3828 / 3829 AM
Rosh Hashanah falls in September/October.
Chinese: Year of the zodiac:Earth zodiac:Dragon
Sexagenary cycle position 5 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 611 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Ethiopian: 60 / 61 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): -10 / -11 Saka
Indian national calendar; year starts in March.

Properties

Parity: Even
Digit count: 2
Digit sum: 14
Digit product: 48
Digital root: 5
Palindrome: No
Bit width: 7 bits
Reversed: 86
Flips to (rotate 180°): 89
Recamán's sequence: a(91) = 68
Square (n²): 4,624
Cube (n³): 314,432
Divisor count: 6
σ(n) — sum of divisors: 126
φ(n) — Euler's totient: 32
Sum of prime factors: 21

Primality

Prime factorization: 2 ² × 17

Nearest primes: 67 (−1) · 71 (+3)

Divisors & multiples

All divisors (6)

1 · 2 · 4 · 17 · 34 (half) · 68

Aliquot sum (sum of proper divisors): 58

Factor pairs (a × b = 68)

1 × 68

2 × 34

4 × 17

First multiples

68 · 136 (double) · 204 · 272 · 340 · 408 · 476 · 544 · 612 · 680

Sums & aliquot sequence

As a sum of two squares: 2² + 8²

As consecutive integers: 5 + 6 + … + 12

Aliquot sequence: 68 → 58 → 32 → 31 → 1 → 0 — terminates at zero

Representations

In words: sixty-eight
Ordinal: 68th
Roman numeral: LXVIII
Binary: 1000100
Octal: 104
Hexadecimal: 0x44
Base64: RA==
One's complement: 187 (8-bit)

In other bases

ternary (3) 2112

quaternary (4) 1010

quinary (5) 233

senary (6) 152

septenary (7) 125

nonary (9) 75

undecimal (11) 62

duodecimal (12) 58

tridecimal (13) 53

tetradecimal (14) 4c

pentadecimal (15) 48

Historical numeral systems

Babylonian (base 60): 𒁹 𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic: 𓎆𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
Greek (Milesian): ξηʹ
Mayan (base 20): 𝋣·𝋨
Chinese: 六十八
Chinese (financial): 陸拾捌

In other modern scripts

Eastern Arabic ٦٨ Devanagari ६८ Bengali ৬৮ Tamil ௬௮ Thai ๖๘ Tibetan ༦༨ Khmer ៦៨ Lao ໖໘ Burmese ၆၈

Digit at this position in famous constants

π — Pi (π): Digit 68 = 8
e — Euler's number (e): Digit 68 = 0
φ — Golden ratio (φ): Digit 68 = 2
√2 — Pythagoras's (√2): Digit 68 = 7
ln 2 — Natural log of 2: Digit 68 = 3
γ — Euler-Mascheroni (γ): Digit 68 = 8

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 68, here are decompositions:

7 + 61 = 68
31 + 37 = 68

ASCII character

As an ASCII codepoint, 68 is D. Printable ASCII character D.

Network port

TCP/UDP port 68 is the well-known port for DHCP client — Dynamic Host Configuration Protocol — client.

Hex color

#000044

RGB(0, 0, 68)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.68.

Address: 0.0.0.68
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.0.68

Unspecified address (0.0.0.0/8) — "this network" placeholder.

US numbered highway

Matches numbered highway designation:

I-68 — Morgantown, WV to Hancock, MD.

Interstate 68 on Wikipedia ↗

Possible US bank routing number

This passes the ABA routing number checksum and matches the Federal Reserve numbering scheme.

Routing number

000000068

Federal Reserve

United States Government

Banks operate many routing numbers per state and division; an unmatched checksum-valid number can still be a real RTN at a smaller institution.

Look up on FedACH (official) ↗ Search Google for routing number 000000068 ↗